Oddly enough the tvOS update 16.1 confused my Samsung TV (Q90T). Got back from a few days away and my Apple TV 4K (3rd gen) had updated while I was away. When I turned my TV on the volume kept reducing to zero, and could not be increased. Tried factory resets of both the TV and the soundbar to no avail. Stumbled on a posting on the Samsung community which blamed the Apple TV and sure enough, a factory reset of the Apple TV 4K fixed the problem. Really don't understand how an Apple TV can affect the TV volume to that extent, but the reset of the ATV has done the trick, which does point the finger at the Apple device...